Self-aligning landing base for off-shore deep water drilling



TOR.

AJK.

WH NF LME :Vfiflvkz U H I An/fl/ AQ I g- 1964 c. E. WAKEFIELD, JR

SELF-ALIGNING LANDING BASE FOR OFF-SHORE DEEP WATER DRILLING Filed Oct. 16. 1961 United States Patent 3,143,172 SELF-ALIGNING LANDENG BASE FQR OFF-SHORE DEEP WATER DRILLING Charles E. Wakefield, Jr., Bakersfield, Calii, assignor to Richfield ()il Corporation, Los Angeles, Calif, 21 corporation of Delaware Filed Oct. 16, 1961, Ser. No. 145,334 8 Claims. (Cl. 16666.5)

The present invention relates to off-shore drilling and production and more specifically relates to apparatus for conducting off-shore drilling and production operations from a floating barge in a formation underlying a body of water particularly in areas where the ocean bottom is sloped or uneven.

Off-shore drilling operations in the past have been conducted through a drilling base such as a flat pre-cast concrete drilling base lowered from the drilling barge or platform to the submarine formation on guide lines. The conductor and surface casings are then run into the Well bore which is drilled through an aperture in the landing base by guiding a drill string through the landing base aperture on the guide lines. Frequently, however, sloping or uneven ocean floors are encountered resulting in alignment difiiculties when the casings and drilling tools are lowered through the landing base. Drilling operations conducted in deep water may also be hampered by the inaccessibility of the well head equipment during both the drilling and the production stages.

It is an object of the present invention to provide a universal self-aligning off-shore landing base for drilling into uneven or sloped submarine formations.

- It is also an object of the present invention to provide an off-shore landing base for drilling into uneven or sloped submarine formations whereby the base is selfaligning relative to the drilling tools and casings as the base encounters and seats on the formation.

It is also an object of the present invention to provide a self-aligning off-shore drilling landing base which can be lowered to the ocean floor with the conductor pipe on a drill pipe or casing riser.

It is a further object of my present invention to provide an off-shore production apparatus with valve containing means surrounding the production head, containing the control valves for controlling the flow of oil through the production head into the oil flow lines.

Other objects and a more complete understanding of my present invention may be had by reference to the following specification and the appended claims taken in conjunction with the drawing in which the drilling base of the present invention and a production head adapted for use therewith are shown in cross-sectional elevation.

Briefly described, my present invention accomplishes the foregoing objects by providing a drilling base having a downwardly tapered socket therein which is adapted to receive and be lowered to the ocean floor simultaneously with a conductor pipe having a ball or an enlargement formed externally thereon near the upper end thereof whereby the base can universally revolve around the ball so that as the base reaches the sloped or uneven submarine formation, it will conform to the slope of the formation by a self-aligning movement of the base, without affecting the substantially vertical position of the conductor pipe with respect to the drilling barge. Al-

3,143,172 Patented Aug. 4, 1964 ice though the expression ocean floor is used in this specification, it is to be understood that my present invention is useful in other bodies of water, such as lakes, seas, etc., as well as oceans.

Referring now more particularly to the drawings, a well 12 is drilled in a submarine formation 14. Production head 10 is releaseably aflixed to a conductor pipe 16 which is supported in the formation by landing base 18. The production head 10 preferably is similar to the head shown and described in my copending application Serial No. 100,411, filed April 3, 1961. The conductor pipe with the landing base thereon is lowered from a drilling barge (not shown) floating on a body of water, into the partially drilled well until the landing base 22 seats on the ocean bottom at the well opening. The base can then universally revolve about the ball 26 with a self-aligning movement until it aligns itself with and seats on or in the formation while the conductor pipe remains substantially vertical, after which the conductor pipe may be cemented into the formation and the landing base. Further drilling operations may then be conducted through the selfaligned, tilted drilling base and the vertical conductor pipe in a substantially vertical manner.

The landing base 18 is shown in its preferred form as of hemispherical configuration, externally, however any external configuration which will establish footing in the formation, preferably by the weight of the base, may be utilized. The double cone design shown is preferable since a lower edge 20 of relatively large diameter, is provided which may readily cut into the formation and establish firm footing for the landing base. The landing base may be a concrete structure or, as shown, the concrete landing base may be pre-cast in a shell or cover 22. Landing base 18 is preferably formed with a downwardly tapering opening 24 which serves as a landing socket for the ball 26 formed around the exterior of the conductor pipe near the top of the conductor pipe.

The ball 26 may be formed on the conductor pipe in any suitable manner, such as by welding thereon or by pressing or forging on a mandrel. The function of the ball 26 may also be performed by an enlargement in the conductor pipe on the order of a rounded shoulder formed in the conductor pipe. It is also within the scope of the present invention to provide a special conductor sub having the landing base 18 formed thereon.

The landing socket 24 may be of a tapered conical or pyramidal shape with the landing socket tapering downwardly so that the ball 26 may seat therein and provide a means whereby the base can rotate about the conductor ball 26 to assume the slope of the formation at the well opening. The amount of taper in the landing socket 24 determines the extent to which the base may be rotated about the ball, that is, an extreme taper would provide for a greater degree of rotation and, consequently, would permit operation in a formation having a greater slope. The landing socket taper preferably utilized in my present invention permits a maximum base rotation of about 30 degrees from horizontal although this taper may be increased or decreased without departing from the spirit of my present invention. The landing socket 24 may taper to the bottom of the landing base 18, however I prefer a double cone design which, as was previously stated, provides a large diameter edge 26 which can readily cut into the formation to establish firm footing therein. In the event that a double cone design is utilized, the taper of the lower cone 28 must be sufficient to permit rotation of the base about the ball 26 preferably to the extent provided for by the taper of the socket 24, shown by the phantom line 30. Otherwise the self-alignment of the landing base about the conductor ball will be restricted by the lower cone.

In order to facilitate the lowering of the base 18 to the formation on the conductor pipe, my present invention provides a suitable retainer structure to confine the ball or enlargement 2-6 to the socket 24. This may be accomplished by fastening a retaining ring 32 to the landing base 13 with a Z clamp 34 which preferably is bolted to the landing base, as shown with bolts 36. This retaining structure permits the landing base 18 to be lowered to the formation with the conductor pipe 16 since the landing base 26 will not pass through the retaining ring opening 38. Hence the landing base of the present invention need not be lowered from the drilling barge to the formation on conventional guide lines since it can be lowered simultaneously with the conductor pipe on the riser or the drill pipe. The conductor pipe 16 with the universal self-aligning landing base 22 thereon is lowered over the drill string after a hole for the conductor pipe has been drilled sufiiciently deep. The base 22 assumes the slope of the formation with the conductor pipe 16 remaining vertical, as previously described. The conductor pipe and landing base are then cemented into the formation.

With the conductor pipe and the landing base set in the well, the blowout preventer and/or riser pipe may be releasably attached to the upper end of the conductor pipe as with a conventional internal release joint and the drilling operations conducted therethrough until pay zones are encountered. At the completion of the drilling operation the blow-out preventer may be removed and a production head lowered onto and latched to the conductor pipe and the well completed in any suitable manner as, for example, the method described in my copending application referred to above. Rather than adding a production head, as shown, the bore 42 of production head 10 may be enlarged and head 16 utilized as both the drilling and production head.

A surface pipe 44 is then seated within the conductor pipe as shown at 45 and a water string 48 seated within the surface pipe as shown at 54 although any conventional method for landing the surface pipe and the Water string may be employed. The tubing string 52 may be hung within the production head It) shown with an automatic tubing hanger 54- on a landing mandrel 56 and a macaroni string 58 supported within the tubing on a macaroni hanger 60 as shown in the drawing and as more completely set forth in my aforementioned copending application.

A water string outlet 62 communicates with the annulus between the tubing and the water string and may be used either for production or injection for secondary recovery. The tubing outlet 64 is provided for the main outlet of oil from the production tubing 52 through the production head. A macaroni outlet 66 is provided for injection purposes and provides access to the well Zones through the tubing string or vice versa.

The valves for receiving the flow from the production head and the actuators therefor are preferably mounted in an oil-filled can 68 which is integral with the production head. By providing a can which houses the various control valves, the valves can be assembled and the production head valve assemblage connected to the production head on shore. The electrically or hydraulically operated valves within the can 68 may be actuated through the electric wires (or hydraulic hoses) 70 which extend to the vessel. Production flows through the flow lines '72 to a production sub-station or other production facilities.

Although my present invention has been described with a certain degree of particularity, the scope of my present ,taaira invention is not to be limited to the details set forth but should be afforded the full breadth of the appended claims.

I claim:

1. Landing base apparatus for use with a conductor pipe in off-shore drilling operations conducted in an underwater formation from floating vessel, comprising in combination: a base member adapted to land on said formation, said base member including means for supporting said conductor in said formation and means associated with said conductor pipe so arranged and proportioned that said conductor pipe is universally movable relative to said base member whereby said conductor pipe maintains substantially vertical alignment irrespective of the slope of said formation on which said base member is landed.

2. The apparatus of claim 1 including means for fixing said conductor pipe relative to said formation in said substantially vertical alignment.

3. Landing base apparatus for use in off-shore drilling operations conducted in an underwater formation from a floating vessel with conductor pipe extending through said apparatus into said formation, comprising in combination: a base member having a downwardly tapered opening forming a socket therein and adapted to land on said formation and receive said conductor pipe extending therethrough into said formation, a rounded enlargement on said conductor pipe near the upper end thereof said enlargement being so arranged and proportioned as to seat in said tapered opening, and whereby said conductor pipe is universally movable relative to said base member so that said conductor pipe maintains substantially vertical alignment irrespective of the slope of said formation on which said base member is landed.

4. The apparatus of claim 3 wherein said landing base has a second tapered opening below the apex of said.

downwardly tapered opening said second tapered opening tapering in the opposite direction to said downwardly tapering opening.

5. The apparatus of claim 4 wherein said second tapered opening tapers suificiently to enable said conductor pipe to move universally in said base member socket the maximum amount permitted by said downwardly tapering socket.

6. The apparatus of claim 4 wherein said second tapered opening tapers sufiiciently to enable said conductor pipe to revolve about said base with a maximum movement of about 30 from vertical.

7. Landing base apparatus for use in off-shore drilling operations conducted in an underwater formation from a floating vessel with conductor pipe extending through said apparatus into said formation, comprising in combination: a base member having a downwardly tapered opening forming a socket therein and adapted to land on said formation and receive said conductor pipe extending therethrough into said formation, a rounded enlargement on said conductor pipe near the upper end thereof said enlargement being so arranged and proportioned as to seat in said tapered opening whereby said base member supports said conductor pipe in said formation, said conductor pipe being universally movable relative to said base member whereby said conductor pipe maintains substantially vertical alignment irrespective of the slope of said formation on which said base member is landed, and means afiixed to said base member for retaining said rounded enlargement in said tapered socket.

8. Landing base apparatusfor use in off-shore drilling operations conducted in an underwater formation from a floating vessel with,conductor pipe extending through said apparatus into said formation, comprising in combination: a base member having a downwardly tapered opening forming a socket therein and adapted to land on said formation and receive said conductor pipe extending therethrough into said formation, a

5 6 rounded enlargement on said conductor pipe near the conductor pipe whereby said base member may be lowupper end thereof said enlargement being so arranged ered from said vessel with said conductor pipe. and proportioned as to seat in said tapered opening whereby said base member supports said conductor pipe References Cited In the file of thls Pawnt in said formation, said conductor pipe being universally 5 UNITED STATES PATENTS movable relative to said base member whereby said con- 2,747,840 Miles May 29, 1956 ductor pipe maintains substantially vertical alignment 970 Knapp et 1 Feb 7 19 1 irrespective of the slope of said formation on which said 2,93 144 Conrad June 3, 19 1 base member is landed, and means for limiting longitudi- 3,004,602 Kofahl Oct. 17, 1961 nal movement of said base member with respect to said 10 3,063,500 Logan Nov. 13, 1962 

1. LANDING BASE APPARATUS FOR USE WITH A CONDUCTOR PIPE IN OFF-SHORE DRILLING OPERATIONS CONDUCTED IN AN UNDERWATER FORMATION FROM FLOATING VESSEL, COMPRISING IN COMBINATION: A BASE MEMBER ADAPTED TO LAND ON SAID FORMATION, SAID BASE MEMBER INCLUDING MEANS FOR SUPPORTING SAID CONDUCTOR IN SAID FORMATION AND MEANS ASSOCIATED WITH SAID CONDUCTOR PIPE SO ARRANGED AND PROPORTIONED THAT SAID CONDUCTOR PIPE IS UNIVERSALLY MOVABLE RELATIVE TO SAID BASE MEMBER WHEREBY SAID CONDUCTOR PIPE MAINTAINS SUBSTANTIALLY VERTICAL ALIGNMENT IRRESPECTIVE OF THE SLOPE OF SAID FORMATION ON WHICH SAID BASE MEMBER IS LANDED. 